The invention relates to a calorimetric flow indicator including a sensor element, which forms a temperature-dependent resistance and which heats up in a short period of time by means of electrical current heat. Resistance variation, induced by cooling, of the sensor represents a measure of flow velocity of a medium flowing by the sensor element and is measured. The sensor element rests against an inner surface of a front wall of a housing projecting into the flowing medium.
Such a flow indicator is known and includes a metal housing having virtually a cylindrical front section projecting into a medium flowing, e.g., in a line. Thus, the measurement result can be falsified or influenced, e.g., due to narrowing of the cross section of the free flow area. Furthermore, with such known flow indicators guaranteeing a repeatable production of heat transmission from the sensor element into the flowing medium, i.e. a reliable heat conduction coupling therebetween, is problematic. Such condition is very important since the measurement effect, i.e. the effect measured as the resistance variation, is usually only a few percent of the temperature-dependent resistance of the sensor,